STS-51G was the 18th flight of NASA's Space Shuttle program and the fifth flight of Discovery. Launched from Kennedy Space Center's Launch Complex 39A on June 17, 1985, the mission carried a seven-person international crew commanded by Daniel Brandenstein with John Creighton as pilot. NASA mission specialists John Fabian, Steven Nagel, and Shannon Lucid flew with French payload specialist Patrick Baudry and Saudi payload specialist Sultan bin Salman bin Abdulaziz Al-Saud. The crew deployed the Morelos-A, Arabsat-A, and Telstar-3D communications satellites, operated the deployable and retrievable SPARTAN-1 astronomy payload, flew Get Away Special canisters, supported a Strategic Defense Initiative tracking experiment, and conducted French biomedical experiments. Discovery landed on Runway 23 at Edwards Air Force Base on June 24, 1985, after 112 revolutions and a mission lasting just over seven days.